Army Testing Mack Dump Trucks

Mack Defense has begun production of five Mack Granite-based model M917A3 Heavy Dump Trucks (HDT). The five trucks are part of the Production Vehicle Testing (PVT) phase of Mack’s $296 million contract with the U.S. Army for armored and armor-capable HDTs.

The Army plans to eventually buy as many as 683 M917A3 armored dump trucks through May 2025. Once these initial five trucks are built, they will start 40 weeks of durability testing at the U.S. Army’s Aberdeen Test Center this summer.

The contract was awarded to Mack Defense in May 2018 and calls for armor-capable or armored HDTs. The trucks, according to the bid, are expected to be used to increase operational effectiveness and readiness, and to support mobility, counter mobility, survivability and sustainment operations for the Joint Forces in areas of the world with austere infrastructures and little or no host nation support.

The HDT’s are based on the civilian Mack Granite trucks and are an 8×8, 94,500 lbs. GVW configuration with a 243 in. wheelbase.

Mack Defense said its engineers optimized the M917A3 HDT to meet the current needs of the U.S. Army, while allowing for evolving requirements and future growth. With heavier-duty rear axles, all-wheel drive and increased suspension ride height, the M917A3 is capable of meeting the payload and mobility requirements set by the U.S. Army HDT program, Mack said.

The HDT’s are powered by a 13 L, 440 hp Mack MP8 diesel with a maximum torque of 1660 lb. ft. The driveline is a Meritor Permalube RPL which drives a six-speed Allison 4500 Gen5 transmission. The front axle is a Meritor MX-810, while the transfer case is a Fabco TC142.

The specs call for the M917A3 to be “capable of individually hauling a variety of dry and wet loads to include blast rock, concrete with reinforcing bars, dirt, hot asphalt, snow, rubble, large boulders and sand and have a rate payload capacity of no less than 22.5 tons for primary and secondary roads and the use of integrated sideboards for on-road payloads; 27 tons for primary and secondary roads and the use of integrated sideboards for on-road payloads.

In addition, the specs require that crew cab and underbody armor protection be capable of being changed out separately based on the mission, without affecting performance. The Army requirement includes both armored and unarmored versions of the M917A3.

The last time the Army bought new dump trucks was in September 2000 when it awarded a $400 million contract to Freightliner to build almost 3400 M917A2’s, as well as M915A3 line haul tractors and M916A3 light equipment transporters.